impulse control

Meaning: Impulse control is part of executive function. It means inhibiting an automatic response, such as an urge, strong emotion or habit, in favor of a long-term goal. The prefrontal cortex exerts top-down control over limbic and reward circuitry (amygdala, nucleus accumbens). In Freud's psychodynamic model, the ego follows the reality principle and restrains the id's demand for immediate satisfaction. Delay of gratification, as in Mischel's marshmallow studies, is a common way to measure it.

On the MCAT: Expect a passage on frontal lobe injury (Phineas Gage) in which a person becomes impulsive and socially inappropriate. A study may compare children who waited longer for a reward with those who did not, and ask about later outcomes. Questions may also ask you to predict why adolescents take more risks (the prefrontal cortex is still maturing while reward-seeking systems are already active) or to match a behavior to the id, ego or superego.

Common confusion: Students treat impulse control as the urge itself. The urge comes from drives (the id, limbic reward activity), while control comes from the ego and prefrontal regulation. Weak control also does not mean low intelligence or paralysis. Gage's speech and movement were largely preserved, while his judgment and self-regulation changed.